Use and composition for protection against organophosphorus poisoning

ABSTRACT

The present invention relates to compositions comprising an antiemetic, particularly including 5-HT3 antagonist and/or NK-1 antagonist antiemetics, in combination with a choline esterase inhibitor such as an acetylcholine esterase inhibitor and/or a butyrylcholine esterase inhibitor, and methods of using the composition to provide improved protection of subjects at risk of organophosphorus poisoning, or, for the treatment, prevention, or alleviation/reduction of toxicity from an organophosphorus compound, by enabling the use of a highly protective daily dose of the choline esterase inhibitor without the typical adverse effects.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/521,667, filed Jun. 19, 2017, and U.S.Provisional Patent Application Ser. No. 62/539,784, filed Aug. 1, 2017,the disclosures of which are incorporated herein in their entirety byreference.

FIELD OF THE INVENTION

The present invention pertains to the field of preventive antidotaltherapy of organophosphorus (OP) poisoning in humans and mammals exposedto or at risk of exposure to OP compounds, a composition comprising anantiemetic selected from 5-HT3 and NK-1 antagonists, in combination withan acetylcholine esterase inhibitor or a butyrylcholine esteraseinhibitor or a choline esterase inhibitor; and a method of using suchcompostions for preventing, treating, or alleviating an effect of an OPcompound. The invention safely enables the efficacy of preventiveantidotal therapy against OP poisoning.

Definitions

“5-HT3 antagonist”: an antagonist of the 5-HT3 receptor subtype-1.

“ACh”: Acetylcholine.

“AChE”: Acetylcholine esterase.

“AChEI”: Acetylcholine esterase inhibitor.

“AE(s)”: Adverse Effect(s).

“BuChE”: Butyrylcholine esterase.

“BuChEI”: Butyrylcholine esterase inhibitor.

“ChE”: Choline esterase.

“ChEI”: Choline esterase inhibitor.

“CNS”: Central Nervous System.

“ER”: Extended Release of the active ingredient from a composition.

“GI”: Gastro-Intestinal.

“IM”: Intramuscular.

“IR”: Immediate Release of the active ingredient from a composition.

“IV”: Intravenous.

“NK-1 antagonist”: neurokinin receptor subtype-1 (NK₁-antagonist), alsoreferred to

-   -   as NK-1 receptor inhibitor or simply NK-1-antagonist.

“OP”: Organophophorus.

“TTS”: Transdermal Therapeutic System.

“Antiemetic”: may include, but is not limited to, a 5-HT3 antagonist, aNK-1 receptor antagonist, a dopamine antagonist, a histamine H1 receptorantagonist, a cannabinoid, a benzodiazepine, and an anticholinergic.

BACKGROUND OF THE INVENTION

The organophosphorus compounds, soman (pinacolylmethylfluorophosphonate), sarin, VX (venomous agent X or ethyl([2-{bis(propan-2-yl)amino]ethyl}sulfanyl)(methyl)phosphinate), andtabun (ethyl dimethylamidocyanophosphate), referred to as nerve agents,are among the most lethal chemical weapons ever developed (Coupland andLeins, 2005). Nerve agents are chemically related to OP insecticidessuch as, but not limited to, chlorpyrifos-oxon, diazinon-oxon, andparaoxon. Intoxication with OP insecticides represents a majorpublic-health concern worldwide (Pohanca, 2014; Karalliedde andSnanayake, 2005; Buckley et al. 2004). Most of the acute toxicity of OPcompounds results from the irreversible inhibition ofacetylcholinesterase (AChE), the enzyme that inactivates theneurotransmitter acetylcholine (ACh) (Bajgar, 2004). However, OPcompounds also inactivate butyrylcholinesterase (BuChE), an enzyme thatscavenges OP compounds as well as inactivating ACh. Inactivation ofBuChE by OP compounds further contributes to toxicity.

OP compounds readily cross the blood-brain-barrier. Consequently,irreversible inhibition of AChE leads to accumulation of fatal amountsof ACh in the periphery and in the brain. In the periphery, AChaccumulation leads to severe muscle fasciculations and subsequentweakness, diarrhea, hypotension, bronchoconstriction, bradycardia,profuse secretions, and miosis. Central nervous system-related effectsinclude anxiety, restlessness, confusion, ataxia, tremors, seizures,cardiorespiratory paralysis, and coma (Albuquerque et al. 2006).

Current therapeutic strategies to decrease OP toxicity includecholinergic receptor antagonists to reduce the muscarinic syndrome,oximes to reactivate OP-inhibited AChE, anticonvulsants to controlOP-triggered seizures, and butyrylcholinesterases to act as OPscavengers (Doctor et al. 1991).

Among other therapies, certain AChE (and BuChE) inhibitors can beprotective of these enzymes by temporarily binding to the enzymes andthus preventing the OP compounds from long term (days) binding to theenzymes. The enzymes are able to function again after a relatively shorttime (hours) when said certain AChE (and BuChE) inhibitors clear thereceptor sites and OP is no longer present. For example, pyridostigminebromide, a quaternary carbamate that does not appreciably cross theblood-brain-barrier, reversibly inhibits AChE and BuChE with similarpotencies, and has been approved for use among military personnel whoare under threat of exposure to nerve agents. Neostigmine is also aquaternary carbamate that does not appreciably cross theblood-brain-barrier, and reversibly inhibits AChE and BuChE with similarpotencies. Rivastigmine and physostigmine, two carbamates that cross theblood-brain-barrier, also reversibly inhibit both AChE and BuChE withsimilar potencies, and should afford better protection against OPintoxication (Triggle et al. 1998; Pohanka, 2014) as they protect AChEand BuChE not only in the periphery, but also in the brain.Physostigmine also interacts directly with, and potentiates nicotinincACh receptors, a disadvantage in a situation where the receptors areexposed to abnormally high amounts of acetylcholine in the synapticcleft. However, physostigmine has the major advantage, when administeredintravenously by bolus, of reaching peak enzyme inhibition (>70%) within2 minutes of administration, and can therefore be useful for allowingfor very rapid protection against OP poisoning (Walter et al, 1995).

Rivastigmine, (S)—N-Ethyl-N-methyl-3-[1-(dimethylamino)ethyl]-phenylcarbamate, inhibits AChE and BuChE in a pseudo-irreversible manner(Darreh-Shori and Soininen, 2010). Slow elimination of rivastigminebecause of the covalent bond in the active site of the enzymes is anadvantage over other ChE inhibitors. The effect of rivastigmine lastsuntil the rivastigmine moiety spontaneously splits from the ChE activesite by a decarbonylation process (Tayeb et al. 2012; Bartolucci et al.2012).

Unfortunately, dose-limiting AEs, consisting mainly of nausea, vomiting,and diarrhea, preclude the use of higher and therefore more effectivedoses of compounds that inhibit both AChE and BuChE, such aspyridostigmine, neostigmine, rivastigmine, and physostigmine.

Pyridostigmine bromide, iodide or methylsulfate is commonly used for thetreatment of myasthenia gravis. Pyridostigmine bromide (Mestinon®) wasapproved by the US Food and Drug Administration (FDA) in 2003 as apretreatment in humans against the lethal effects of the irreversiblenerve agent soman. Studies in primates (Haigh et al, 2010) showed thatAChE activity in red blood cells was inhibited by 18% and 50%respectively by a low (12.5 μg/kg) and a high (39.5 μg/kg)pyridostigmine dose. By contrast soman inhibited 98% of AChE activity inred blood cells (and, in a chemical warfare context, soman would disruptAChE activity for days while pyridostigmine would inhibit AChE activityonly for a few hours while protecting the binding sites from OPcompounds). Clearly, a higher dose of pyridostigmine could further andmore efficiently protect against soman poisoning, but dose-limitinggastro-intestinal side effects preclude the use of higher doses.

Neostigmine is commercially available as a brand or generic drug, forexample as oral Prostigmin®, consisting of tablets comprising 15 mgneostigmine bromide and vials for parenteral injection comprising 0.5 mgof neostigmine methylsulfate, a 15 mg of neostigmine bromide oral dosebeing equivalent to 0.5 mg of neostigmine methylsulfate parenteral dose.

A neostigmine bromide slow release preparation which can be taken onceevery day for treating myasthenia gravis is described in CN 102258492,the contents of which are incorporated herein in their entirety forreference.

Neostigmine is also described in combination with some plant extractsaccording to traditional Chinese medicine (CN 102552381), for treatingmyasthenia gravis.

A process for the synthesis of neostigmine iodide and neostigminemethylsulfate is disclosed in RU 2010130899, the contents of which areincorporated herein in their entirety by reference.

Neostigmine methylsulfate has been disclosed as a remedy for eyediseases, in an eye drop preparation, consisting of a neostigminemethylsulfate aqueous solution, also containing other chemicals,emulsified with an oily higher fatty acid solution obtained from oliveoil and isopropyl myristate (JPS 56104814, the contents of which areincorporated herein in their entirety by reference).

Neostigmine methylsulfate has also been disclosed, in combination withnaphazoline hydrochloride and chlorpheniramine maleate, for thetreatment of conjunctivitis (CN 105708838, the contents of which areincorporated herein in their entirety by reference).

Physostigmine, a reversible cholinesterase inhibitor also known aseserine, was described in the early 1980s as protective against somanpoisoning but based on its side effects, pyridostigmine was judged to bea preferable treatment (Xia et al, 1981). Heckert et al. (2011) showedthat in guinea pigs prophylactic pretreatment with physostigmineprevented complete inhibition of AChE by soman and resulted in partialspontaneous recovery of the enzyme by de-carbamylation. More recently, atransdermal patch system containing procyclidine, anN-methyl-d-aspartate receptor antagonist possessing anticholinergicaction, and physostigmine, was developed, and its prophylactic efficacyagainst soman intoxication was investigated (Cho et al, 2012). Malerhesus monkeys were shaved on the dorsal area, and a matrix-type patchapplied, with various sizes (2×2 to 7×7 cm) for 24 or 72 h, andchallenged with 2×LD₅₀ doses (13μg/kg) of soman. The smallest patch sizefor the protection against lethality induced by soman intoxication was3×3 cm, resulting in a blood procyclidine concentration of 10.8 ng/ml, ablood physostigmine concentration of 0.54 ng/ml, and a bloodcholinesterase inhibition of 42%. The drug concentrations and enzymeinhibition rate corresponding to a diverging point of survivability wereestimated to be around 7 ng/ml for procyclidine, 0.35 ng/ml forphysostigmine, and 37% of enzyme inhibition.

Arcava et al. (2009), reported on the use of pretreatment with highdoses of rivastigmine to protect guinea pigs against soman toxicity.Rivastigmine is a AChE inhibitor that crosses the blood-brain-barrier.It is approved as a transdermal patch and as an oral formulation for thetreatment of Alzheimer's disease. However, when given alone in dosesthat are tolerated, rivastigmine has been reported to inhibit onlyapproximately 20% to 30% of AChE activity in human brain (Kaasinen etal, 2002).

Dose-limiting gastro-intestinal adverse effects of all of theabove-described AChEIs and BuChEIs consist mainly of nausea, vomiting,and diarrhea. As a consequence of these dose-limiting side effects,protection against nerve agents and certain insecticides and pesticidesis reduced and incomplete.

Thus, the problem of providing safe, chronic pretreatment against deadlyOP compounds with the approved therapeutic doses for pyridostigmine,neostigmine, physostigmine, and rivastigmine remains unsolved.

SUMMARY OF THE INVENTION

The present invention relates to the use of an antiemetic, and inparticular, a 5-HT3 receptor antagonist and/or a NK-1 receptorantagonist, in combination with a ChEI. It has now been found that it ispossible, with such a combination, to pretreat humans or other mammalsthat are at risk of being exposed to lethal doses of OP compounds, byenabling the safe administration of a fully protective dose of a ChEinhibitor such as pyridostigmine bromide, neostigmine, rivastigmine, orphysostigmine.

In particular embodiments, it has been found that a 5-HT3 antagonist, ora NK-1 antagonist, by reducing or even abrogating the side effects ofhigh doses of ChEIs, enables higher doses of the ChEI to be safelyadministered and thus enabling greater protection against OP poisoning.

In particular embodiments, the present invention provides a combinationof a 5-HT3 antagonist and a NK-1 antagonist to reduce or abrogate theside effects of high doses of ChEIs, and enable higher doses of the ChEIto be safely administered and thus provide greater protection against OPpoisoning.

The present invention provides a pharmaceutical composition containingan effective daily dose of an antiemetic and an effective daily dose ofa choline esterase inhibitor. The antiemetic is preferably selected froma 5-HT3 antagonist and a NK-1 antagonist.

The present invention also provides a pharmaceutical compositioncomprising an antiemetic combination and an effective daily dose of acholine esterase inhibitor. The antimetic combination is preferably, acombination of a 5-HT3 antagonist and a NK-1 antagonist.

The 5-HT3 antagonist is present in an amount up to 10 times a pediatricor adult dose approved for the prevention of chemotherapy-induced nauseaand vomiting.

The NK-1 antagonist is present in an amount up to 6 times a pediatric oradult dose approved for the prevention of chemotherapy-induced nauseaand vomiting. Thus, the present invention also provides compositions andmethods for alleviating/reducing or preventing OP poisoning thatcomprise administering to a patient in need of said treatment acombination of a 5-HT3 antagonist and/or a NK-1 antagonist, with a fullyeffective dose of a ChEI such as an AChE inhibitor and/or a BuChEinhibitor.

DETAILED DESCRIPTION

Other objects and advantages of the present invention will becomeapparent from the following detailed description together with theappended claims.

The present invention provides methods and compositions useful forsafely improving the protection of humans and other mammals at risk ofbeing exposed to OP compounds, and pre-treated with a ChE inhibitor, bychronic or recurrent administration of an antiemetic such as a 5-HT3antagonist, an NK-1 antagonist, or combination thereof, to said humansand other mammals. The present invention also provides methods andcompositions useful for safely treating, preventing, oralleviating/reducing an effect of an OP compound in humans and mammalsexposed to an OP compound.

Toxicity or symptoms of toxicity following exposure to nerve agents (OPcompounds) include, but are not limited to, a runny nose, coughing,tightness in the chest, difficulty breathing or shortness of breath,constriction of the pupils, blurry vision, profuse salivation,involuntary salivation, muscle twitching, seizures/convulsions,involuntary urination, involuntary defecation, lacrimate,gastrointestinal pain, nausea, vomiting, blisters and burning of theeyes and/or lungs, respiratory depression, and death.

Any of the antimetics such as 5-HT3 antagonists, NK-1 antagonists, orcombinations thereof, disclosed in the literature may be used incombination with a dose of an ChEI including, but not limited to,pyridostigmine, neostigmine, physostigmine, and/or rivastigmine thatmaximally inhibits ChE in the periphery (pyridostigmine; neostigmine) aswell as in the central nervous system (rivastigmine; physostigmine). Thechronic or recurrent use of this combination increases the protectionafforded by the ChEI by concurrently mitigating or even eliminating theadverse effects induced by these ChE inhibitors alone.

According to the present invention, preferably, the 5-HT3 or NK-1antagonists used are those approved for preventing nausea and vomitingfollowing cancer chemotherapy.

In particular, surprisingly, 5-HT3 or NK-1 antagonists, known to blocknausea, vomiting, and diarrhea induced by chemotherapeutic drugs, havebeen shown, when administered, for 5-HT3 antagonists administered athigh doses, and for NK-1 antagonists at doses in the range from 60% ofrecommended doses to doses higher than recommended doses, to also blockthe gastro-intestinal side effects of AChE inhibitors.

This finding is surprising also because to date no one thought that, bycombining an effective dose of a 5-HT3 antagonist, a NK1-antagonist, ora combination thereof, with an effective dose of ChE inhibitors, itwould have been possible to safely improve the protection of humans atrisk of being exposed to lethal amounts of an OP compound, or to safelytreat, prevent or alleviate/reduce an effect of an OP compound in humansor other mammals exposed to lethal amounts of an OP compound.

Thus, the present invention provides a method for protecting humans orother mammals at risk of OP poisoning, which comprises administering toa patient in need of said treatment an effective daily dose of anantiemetic such as a 5-HT3 antagonist, or of a NK-1 antagonist,administered orally as IR, ER, sustained release (SR) or sublingualtablets, intramuscularly, subcutaneously, or intravenously incombination with an effective daily dose of a pharmaceuticallyacceptable salt of pyridostigmine, neostigmine, rivastigmine, orphysostigmine administered orally as IR, ER, SR or sublingual tablets,intramuscularly, subcutaneously, or intravenously. The intravenous routehas the advantage of reaching effective concentrations within minutes,allowing for fast protection against an OP exposure, but has thedisadvantage of a relatively short duration of action, approximating 1to 2 hours, and therefore requiring repeat administrations.

The present invention also provides a method for protecting humans orother mammals at risk of OP poisoning, which comprises administering toa patient in need of said treatment an effective daily dose ofantiemetic such as a 5-HT3 antagonist and an effective daily dose ofantiemetic such as a NK-1 antagonist, administered in combination orallyas IR, ER, sustained release (SR) or sublingual tablets,intramuscularly, subcutaneously, or intravenously in combination with aneffective daily dose of a pharmaceutically acceptable salt ofpyridostigmine, neostigmine, rivastigmine, or physostigmine administeredorally as IR, ER, SR or sublingual tablets, intramuscularly,subcutaneously, or intravenously.

EMBODIMENTS

The terms “effective daily dose of 5-HT3 antagonist” and “effectivedaily dose of NK-1 antagonist”, as used herein refer, respectively, to adose of said 5-HT3 antagonist or to a dose of said NK-1 antagonist thatis at least as high as or equal to a dose used to treat or preventnausea and vomiting in pediatric or adult patients undergoing cancerchemotherapy according to the current protocols for said treatment. Inparticular preferred embodiments, a dose of said 5-HT3-antagonist ishigher or greater than an effective daily dose of 5HT3-antagonist and adose of said NK-1 antagonist is higher or greater than an effectivedaily dose of NK-1 antagonist.

According to particular embodiments, the invention providespharmaceutical combinations comprising an antiemetic, where theantiemetic is a 5-HT3 antagonist or a NK-1 antagonist, at a dose that isat least as high as or equal to the pediatric or adult dose approved forthe prevention of chemotherapy-induced nausea and vomiting, and aneffective dose of a pharmaceutically acceptable salt of pyridostigmine,neostigmine, rivastigmine, or physostigmine. In further embodiments, theinvention provides pharmaceutical combinations comprising an antiemetic,where the antiemetic is a 5-HT3 antagonist or a NK-1 antagonist, at adose that is higher or greater than the pediatric or adult dose approvedfor the prevention of chemotherapy-induced nausea and vomiting, and aneffective dose of a pharmaceutically acceptable salt of pyridostigmine,neostigmine, rivastigmine, or physostigmine.

According to other particular embodiments, the invention providespharmaceutical combinations comprising a 5-HT3 antagonist and a NK-1antagonist, each at a dose that is at least as high as or equal to thepediatric or adult dose approved for the prevention ofchemotherapy-induced nausea and vomiting, and an effective dose of apharmaceutically acceptable salt of pyridostigmine, neostigmine,rivastigmine, or physostigmine. In further embodiments, the inventionprovides pharmaceutical combinations comprising a 5-HT3 antagonist and aNK-1 antagonist, each at a dose that is higher or greater than thepediatric or adult dose approved for the prevention ofchemotherapy-induced nausea and vomiting, and an effective dose of apharmaceutically acceptable salt of pyridostigmine, neostigmine,rivastigmine, or physostigmine.

According to further embodiments, the invention provides an antiemetic,where the antiemetic is a 5-HT3 antagonist or a NK-1 antagonist, inpharmaceutical compositions comprising, as an active ingredient, saidantiemetic in an amount at least as high as or equal to the pediatric oradult dose approved for the prevention of chemotherapy-induced nauseaand vomiting, in admixture with a pharmaceutical carrier, for use forpreventing or curing the adverse effects of pyridostigmine inpretreatment of OP poisoning. In alternative embodiments, the inventionprovides an antiemetic, where the antiemetic is a 5-HT3 antagonist or aNK-1 antagonist, in pharmaceutical compositions comprising, as an activeingredient, said antiemetic in an amount higher or greater than thepediatric or adult dose approved for the prevention ofchemotherapy-induced nausea and vomiting, in admixture with apharmaceutical carrier, for use for preventing or abrogating the adverseeffects of pyridostigmine in pretreatment of OP poisoning.

According to further embodiments, the invention provides an antiemeticcombination, where the antiemetic combination is a 5-HT3 antagonist anda NK-1 antagonist, in pharmaceutical compositions comprising saidantiemetic combination and where the 5-HT3 antagonist and a NK-1antagonist are each in an amount at least as high as or equal to thepediatric or adult dose approved for the prevention ofchemotherapy-induced nausea and vomiting, in admixture with apharmaceutical carrier, for use for preventing or curing the adverseeffects of pyridostigmine in pretreatment of OP poisoning. Inalternative embodiments, the invention provides an antiemeticcombination, where the antiemetic combination is a 5-HT3 antagonist anda NK-1 antagonist, in pharmaceutical compositions comprising saidantiemetic combination and where the 5-HT3 antagonist and the NK-1antagonist are each in an amount higher or greater than the pediatric oradult dose approved for the prevention of chemotherapy-induced nauseaand vomiting, in admixture with a pharmaceutical carrier, for use forpreventing or abrogating the adverse effects of pyridostigmine inpretreatment of OP poisoning.

According to further embodiments, the invention includes the use of anantiemetic, where the antiemetic is a 5-HT3 antagonist or a NK-1antagonist, for the preparation of medicaments consisting of apharmaceutical composition comprising, as an active ingredient, saidantiemetic, in an amount at least as high as or equal to the pediatricor adult dose approved for the prevention of chemotherapy-induced nauseaand vomiting, in admixture with a pharmaceutical carrier, for preventingor curing the adverse effects of pyridostigmine in the pretreatment ofOP poisoning. The invention also includes the use of an antiemetic,where the antiemetic is a 5-HT3 antagonist or a NK-1 antagonist for thepreparation of medicaments consisting of a pharmaceutical compositioncomprising, as an active ingredient, said antiemetic, in an amounthigher or greater than the pediatric or adult dose approved for theprevention of chemotherapy-induced nausea and vomiting, in admixturewith a pharmaceutical carrier, for preventing or curing the adverseeffects of pyridostigmine in the pretreatment of OP poisoning.

According to further embodiments, the invention includes the use of anantiemetic combination, where the antiemetic combination is a 5-HT3antagonist and a NK-1 antagonist, for the preparation of medicamentsconsisting of a pharmaceutical composition comprising said antiemeticcombination where the 5-HT3 antagonist and the NK-1 antagonist are eachin an amount at least as high as or equal to the pediatric or adult doseapproved for the prevention of chemotherapy-induced nausea and vomiting,in admixture with a pharmaceutical carrier, for preventing or curing theadverse effects of pyridostigmine in the pretreatment of OP poisoning.The invention also includes the use of an antiemetic combination, wherethe antiemetic combination is a 5-HT3 antagonist and a NK-1 antagonistfor the preparation of medicaments consisting of a pharmaceuticalcomposition comprising, said antiemetic combination where the 5-HT3antagonist and the NK-1 antagonist are each in an amount higher orgreater than the pediatric or adult dose approved for the prevention ofchemotherapy-induced nausea and vomiting, in admixture with apharmaceutical carrier, for preventing or curing the adverse effects ofpyridostigmine in the pretreatment of OP poisoning.

As set forth above, the amount of the antiemetic, where the antiemeticis a 5-HT3 antagonist or a NK-1 antagonist, is at least as high as orequal to, the pediatric or adult dose approved for the prevention ofchemotherapy-induced nausea and vomiting and may in the case of 5-HT3antagonists be up to 10 times said dose, and in the case of NK-1antagonists be up to 6 times said dose. Alternatively, the amount of theantiemetic, where the antiemetic is a 5-HT3 antagonist or aNK-1-antagonist, is higher or greater than the pediatric or adult doseapproved for the prevention of chemotherapy-induced nausea and vomitingand may in the case of 5-HT3 antagonists be up to 10 times said dose,and in the case of NK-1 antagonists be up to 6 times said dose.

According to yet further embodiments, the invention providespharmaceutical fixed-dose combinations consisting of a pharmaceuticalcomposition comprising an antiemetic, where the antiemetic is a 5-HT3antagonist or a NK-1 antagonist, in an amount that is at least as highas or equal to, the pediatric or adult dose approved for the preventionof chemotherapy-induced nausea and vomiting, as Component (a) and aneffective dose of a pharmaceutically acceptable salt of pyridostigmine,neostigmine, rivastigmine, or physostigmine as Component (b), inadmixture with a pharmaceutical carrier or vehicle. In alternativeembodiments, the invention provides pharmaceutical fixed-dosecombinations consisting of a pharmaceutical composition comprising anantiemetic, where the antiemetic is a 5-HT3 antagonist or a NK-1antagonist, in an amount that is higher or greater than the pediatric oradult dose approved for the prevention of chemotherapy-induced nauseaand vomiting, as Component (a) and an effective dose of apharmaceutically acceptable salt of pyridostigmine, neostigmine,rivastigmine, or physostigmine as Component (b), in admixture with apharmaceutical carrier or vehicle.

According to yet further embodiments, the invention providespharmaceutical fixed-dose combinations consisting of a pharmaceuticalcomposition comprising an antiemetic combination, where the antiemeticcombination is a 5-HT3 antagonist and a NK-1 antagonist, where the 5-HT3antagonist and the NK-1 antagonist are each in an amount that is atleast as high as or equal to, the pediatric or adult dose approved forthe prevention of chemotherapy-induced nausea and vomiting, as Component(a) and an effective dose of a pharmaceutically acceptable salt ofpyridostigmine, neostigmine, rivastigmine, or physostigmine as Component(b), in admixture with a pharmaceutical carrier or vehicle. Inalternative embodiments, the invention provides pharmaceuticalfixed-dose combinations consisting of a pharmaceutical compositioncomprising an antiemetic combination, where the antiemetic combinationis a 5-HT3 antagonist and a NK-1 antagonist, where the 5-HT3 antagonistand the NK-1 antagonist are each in an amount that is higher or greaterthan the pediatric or adult dose approved for the prevention ofchemotherapy-induced nausea and vomiting, as Component (a) and aneffective dose of a pharmaceutically acceptable salt of pyridostigmine,neostigmine, rivastigmine, or physostigmine as Component (b), inadmixture with a pharmaceutical carrier or vehicle.

The dose of pyridostigmine IR normally as bromide per tablet will rangefrom 30 mg to 90 mg, depending on safety and tolerability (per day thedose ranges from approx. 240 mg to 1080 mg). The dose of pyridostigmineExtended Release (ER) per tablet will range from 90 to 360 mg per tablet(per day the dose ranges from approx. 500 mg to 3000 mg). The dose ofneostigmine, normally as bromide, in an IR tablet will range from 15 mgto 75 mg, depending on safety and tolerability. The dose of rivastigminenormally as tartrate in an IR tablet will range from 6 to 24 mg, in adaily patch the dose will range from 9.5 mg/day to 47.5 mg/day,depending on safety and tolerability. The dose of oral IR or sublingualphysostigmine will range from 3.5 mg daily to 32 mg daily, given individed doses every 2 hours. The dose of ER physostigmine will rangefrom 9 mg to 15 mg administered every 4 hours. The dose of physostigmineadministered IR will range from 0.5 mg to 2 mg administered every 20min. The amount of physostigmine administered by TTS will range from 3to 12 mg over 24 hours; the dose by intravenous bolus injection willrange from 100 ug/kg to 300 ug/kg. An advantage of the intravenous routeis that maximal inhibition in plasma (>78%) is reached in 2 minutes,allowing for very rapid protection against OP poisoning.

5-HT3 Antagonists

When the 5-HT3 antagonist is ondansetron, the dose per tablet incombination with pyridostigmine is from 4 mg to 8 mg (per day the doseranges from 8 to 12 mg).

When the 5-HT3 antagonist is dolasetron, the dose per tablet incombination with pyridostigmine is from 100 mg to 200 mg.

Ondansetron may also be present in a slow-release oral composition, orin an intravenous preparation

The 5-HT3 antagonist is preferably selected from the group consisting of5-methyl-2-[(4-methyl-1H-imidazol-5-yl)methyl]-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indol-1-one(alosetron) and pharmaceutically acceptable salts and solvates thereof,especially its hydrochloride, disclosed in U.S. Pat. No. 5,360,800,which is herein incorporated by reference in its entirety;6-chloro,3,4-dihydro-4-methyl-3-oxo-N-(quinuclidinyl)-2H-1,4-benzoxazine-8-carboxamide(azasetron) and pharmaceutically acceptable salts and solvates thereof,especially its hydrochloride, disclosed in U.S. Pat. No. 4,892,872,which is herein incorporated by reference in its entirety;[(1S,5R)-8-methyl-8-azabicyclo[3.2.1]octan-3-yl]3,5-dichlorobenzoate(bemesetron, CAS: 40796-97-2);(10R)-10-[(2-methyl-1H-imidazol-1-yl)methyl]-5,6,9,10-tetrahydro-4H-pyrido(3,2,1-jk)carbazol-11-one(cilansetron) and pharmaceutically acceptable salts and solvatesthereof, especially its hydrochloride monohydrate, disclosed in U.S.Pat. No. 4,939,136, which is herein incorporated by reference in itsentirety; (3R)-10-oxo-8-azatricyclo[5.3.1.03,8]undec-5-yl1H-indole-3-carboxylate (dolasetron) and pharmaceutically acceptablesalts and solvates thereof, especially its monomethanesulfonatemonohydrate, disclosed in U.S. Pat. No. 4,906,755, which is hereinincorporated by reference in its entirety;(+)—(R)-8,9-dihydro-10-methyl-7-[(5-methylimidazol-4-yl)methyl]pyrido[1,2-a]indol-6(7H)-one(fabesetron) and pharmaceutically acceptable salts and solvates thereof,especially its hydrochloride or maleate, disclosed in U.S. Pat. No.5,141,945, which is herein incorporated by reference in its entirety;1-methyl-N-((1R,3r,5S)-9-methyl-9-azabicyclo[3.3.1]nonan-3-yl)-1H-indazole-3-carboxamide(granisetron) and pharmaceutically acceptable salts and solvatesthereof, especially its hydrochloride, disclosed in U.S. Pat. No.4,886,808, which is herein incorporated by reference in its entirety;2,3-dihydro-N-(8-methyl-8-azabicyclo[3.2.1]oct-3-yl)-2-oxo-1H-benzimidazole-1-carboxamide(itasetron) and pharmaceutically acceptable salts and solvates thereof,especially its hydrochloride, disclosed in U.S. Pat. No. 5,223,511,which is herein incorporated by reference in its entirety;1-phenylmethyl-2-(1-piperazinyl)-1H-benzimidazole (lerisetron) andpharmaceutically acceptable salts and solvates thereof, specially itshydrochloride, disclosed in U.S. Pat. No. 5,256,665 and, in atransdermal preparation, in U.S. Pat. No. 6,136,807, the disclosures ofwhich are herein incorporated by reference in their entirety;6-fluoro-5-methyl-2-[(5-methyl-1H-imidazol-4-yl)methyl]-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indol-1-one(lurosetron, CAS 128486-54-4) and pharmaceutically acceptable salts andsolvates thereof, especially its mesylate (GR 87442 N); (±)1,2,3,9-tetrahydro-9-methyl-3-[(2-methyl-1H-imidazol-1-yl)methyl]-4H-carbazol-4-one(ondansetron) and pharmaceutically acceptable salts and solvatesthereof, especially its hydrochloride dihydrate, disclosed in U.S. Pat.No. 4,695,578, which is herein incorporated by reference in itsentirety;(3a5)-2-[(S)-1-azabicyclo[2.2.2]oct-3-yl]-2,3,3a,4,5,6-hexahydro-1-oxo-1H-benz[de]isoquinoline(palonosetron) and pharmaceutically acceptable salts and solvatesthereof, especially its hydrochloride, disclosed in U.S. Pat. No.5,202,333, which is herein incorporated by reference in its entirety;1-methylindol-3-yl)-[(5R)-4,5,6,7-tetrahydro-3H-benzimidazol-5-yl]methanone(ramosetron) and pharmaceutically acceptable salts and solvates thereof,especially its fumarate, disclosed in U.S. Pat. No. 5,344,927, which isherein incorporated by reference in its entirety;endo-N-(8-methyl-8-azabicyclo[3.2.1]oct-3-yl)-2,3-dihydro-3,3-dimethyl-indole-1-carboxamide(3,3-dimethyl-N— 1αH,5αH-tropan-3α-yl-1-indolinecarboxamide, ricasetron,CAS 117086-68-7) and pharmaceutically acceptable salts and solvatesthereof, especially its hydrochloride; the(3-endo)-8-methyl-8-azabicyclo[3.2.1]oct-3-yl ester of1H-indole-3-carboxylic acid (3-tropanylindole-3-carboxylate,tropisetron) and pharmaceutically acceptable salts and solvates thereof,especially its hydrochloride, disclosed in U.S. Pat. No. 4,789,673,which is herein incorporated by reference in its entirety; and5-chloro-2,2-dimethyl-N-(8-methyl-8-azabicyclo[3.2.1]oct-3-yl)-2,3-dihydro-1-benzofuran-7-carboxamide(zatosetron) and pharmaceutically acceptable salts and solvates thereof,especially its maleate, disclosed in U.S. Pat. No. 5,563,148, which isherein incorporated by reference in its entirety.

Antagonists of the 5-HT3 receptor that are approved for the preventionof chemotherapy-induced nausea and vomiting are particularly usefulaccording to the present invention. In particular, azasetronhydrochloride, commercially available in 10-mg tablets; dolasetronmonomethanesulfonate monohydrate (also referred to as dolasetronmesylate), commercially available in 200-mg maximal dose tablet;granisetron hydrochloride, commercially available in 2.24 mg maximaldose tablet; ondansetron hydrochloride dihydrate, commercially availablein 10 mg maximal dose tablet; palonosetron hydrochloride, commerciallyavailable in 0.56 mg tablets; and tropisetron hydrochloride,commercially available in 5.64 mg capsules; are the preferred 5-HTantagonists.

NK-1 Antagonists

When the NK-1 antagonist is aprepitant, the dose per tablet, incombination with pyridostigmine, is from 80 mg to 120 mg of aprepitant.

When the NK-1 antagonist is aprepitant, the dose per tablet incombination with pyridostigmine IR is 80 mg to 120 mg of aprepitant.Likewise, when the NK-1 antagonist is aprepitant, the dose per tablet incombination with pyridostigmine ER is 80 mg to 120 mg of aprepitant.

The NK-1 antagonist Component (a) preferably includes, but is notlimited to:

-   5-[[(2R,3S)-2-R1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy]-3-(4-fluorophenyl)-4-morpholinyl]methyl]-1,2-dihydro-3H-1,2,4-triazol-3-one    (aprepitant); described in U.S. Pat. No. 5,719,147, and in a liquid    oral formulation, in US 2017/0035774, the disclosures of which are    incorporated herein in their entirety by reference;-   [3-1R2R,3S)-2-[(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy]-3-(4-fluorophenyl)morpholin-4-yl]methyl}-5-oxo-2H-1,2,4-triazol-1-yl]phosphonic    acid(fosaprepitant), disclosed, for example as meglumine salt in    U.S. Pat. No. 5,691,336 and as di(cyclohexylamine) salt in US    2016/355533, the disclosures of which are incorporated herein in    their entirety by reference;-   (2S,4S)-4-(4-Acetyl-1-piperazinyl)-N—R1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethyl]-2-(4-fluoro-2-methylphenyl)-N-methyl-1-piperidinecarboxamide    (casopitant) described in U.S. Pat. No. 7,294,630, the disclosure of    which is incorporated herein in its entirety by reference;-   (2S,3S)—N-(5-tert-Butyl-2-methoxybenzyl)-2-(diphenylmethyl)-1-azabicyclo[2.2.2]octan-3-amine    (maropitant);-   (2S,3S)-2-Diphenylmethyl-3-[(5-isopropyl-2-methoxybenzyl)amino]quinuclidine    (eziopitant), disclosed by Evangelista S (2001). “Eziopitant.    Pfizer”; Current Opinion in Investigational Drugs: 2 (10): 1441-3;    reviewed in Drugs: the Investigational Drugs Journal 6 (8): 758-72,    the disclosure of which is incorporated herein in its entirety by    reference;-   N-[(2R)-1-[Acetyl-[(2-methoxyphenyl)methyl]amino]-3-(1H-indol-3-yl)propan-2-yl]-2-(4-piperidin-1-ylpiperidin-1-yl)acetamide    (lanepitant);-   2-[3,5-bis(trifluoromethyl)phenyl]-N,2-dimethyl-N-[4-(2-methylphenyl)-6-(4-methyl-1-piperazinyl)-3-pyridinyl]propanamide    (netupitant) described in U.S. Pat. Nos. 6,297,375, 6,719,996 and    6,593,472, the disclosures of which are incorporated herein in their    entirety by reference;-   (2R,4S)-4-[(8aS)-6-oxo-1,3,4,7,8,8a-hexahydropyrrolo[1,2-a]pyrazin-2-yl]-N—R1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethyl]-2-(4-fluoro-2-methylphenyl)-N-methylpiperidine-1-carboxamide    maleate (orvepitant), described in U.S. Pat. No. 7,652,012 and U.S.    Pat. No. 8,309,553, the disclosures of which are incorporated herein    in their entirety by reference;-   (5S,8S)-8-({(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy}methyl)-8-phenyl-1,7-diazaspiro[4.5]decan-2-one    (rolapitant), described in U.S. Pat. No. 7,049,320 and, for an    injectable form thereof, in U.S. Pat. No. 9,101,615, the disclosures    of which are incorporated herein in their entirety by reference;-   3-((3aR,4R,5S,7a5)-5-[(1R)-1-[3,5-bis(trifluoromethylphenyl]ethoxy]-4-(4-fluorophenyl)-1,3,3a,4,5,6,7,7a-octahydroisoindol-2-ylcyclopent-2-en-1-one    (serlopitant) described in U.S. Pat. Nos. 7,544,815 and 7,217,731,    the disclosures of which are incorporated herein in their entirety    by reference;-   2-(S)-(4-Fluoro-2-methyl-phenyl)-piperazine-1-carboxylic acid    [1-(R)-(3,5-bis-trifluoromethyl-phenyl)-ethyl]-methyl-amide    (vestipitant), described in WO 2001/25219 and, in intravenous    formulation having a reduced tendency to cause hemolysis, in WO    2012/175434, the disclosures of which are incorporated herein in    their entirety by reference; and    -   (2S,3S)—N-[(2-methoxy-5-]5-(trifluoromethyl)tetrazol-1-yl[phenylmethyl]-2-phenylpiperidin-3-amine        (vofopitant), disclosed by Gardner CJ et al. Regul Pept. 1996        Aug 27;65(1):45-53. the disclosure of which is incorporated        herein in its entirety by reference.

Antagonists of the NK-1 receptor that are approved for the prevention ortreatment of postoperative nausea and vomiting or for the prevention ofchemotherapy-induced nausea and vomiting are particularly usefulaccording to the present invention. In particular, aprepitant iscommercially available (Emend®) in capsules containing 40 mg, 80 mg, or125 mg aprepitant or, as fosaprepitant dimeglumine (Emend® Injection),in vials containing 115 mg or 150 mg fosaprepitant; rolapitant isavailable (Varubi®) in 90-mg tablets; and netupitant is available(Akynzeo®) in a fixed-dose combination in capsules containing 300 mg ofnetupitant and 0.5 mg of the 5-HT3 antagonist palonosetron (ashydrochloride), herein below referred to as “netupitant300mg/palonosetron0.5 mg”. Each of these preparations is a particularlyadvantageous NK-1 antagonist Component (a) for the combination withChEIs such as pyridostigmine, neostigmine, rivastigmine, orphysostigmine and the pharmaceutically acceptable salts and solvatesthereof as Component (b) according to the present invention.

Preferably, for said use in the prevention or treatment of OP in asubject, said NK1-antagonist Component (a) is aprepitant at a daily oraldose of from 80 mg to 120 mg; rolapitant, at a daily oral dose of from30 mg to 270 mg or netupitant 300 mg/palonosetron0.5 mg, orallyadministered once a day, each in combination with a ChEI such aspyridostigmine, or rivastigmine, or neostigmine, or physostigmine, or apharmaceutically acceptable salt thereof as Component (b) at a dailydose equivalent to up to 4.7 times higher than the maximum recommendeddose for the treatment of Alzheimer's disease.

In carrying out the method of the present invention, the daily dose ofthe antiemetic, where the antiemetic is a 5-HT3 antagonist or a NK-1antagonist, is at least as high as or equal to the dose used to preventnausea and vomiting in pediatric or adult patients undergoing cancerchemotherapy according to the current protocols for said treatment. Inalternative embodiments, in carrying out the method of the presentinvention, the daily dose of the antiemetic, where the antiemetic is a5-HT3 antagonist or a NK-1 antagonist, is higher or greater than thedose used to prevent nausea and vomiting in pediatric or adult patientsundergoing cancer chemotherapy according to the current protocols forsaid treatment.

For use in the treatment of OP poisoning in combination withpyridostigmine, an antiemetic, where the antiemetic is a 5-HT3antagonist or a NK-1 antagonist, is formulated in a pharmaceuticalcomposition, wherein said antiemetic is in admixture with apharmaceutical carrier or vehicle.

For use in the treatment of OP poisoning in combination withpyridostigmine, an antiemetic combination, where the antiemeticcombination is a 5-HT3 antagonist and a NK-1 antagonist, is formulatedin a pharmaceutical composition, wherein said antiemetic combination isin admixture with a pharmaceutical carrier or vehicle.

The composition of this invention may be provided as a pharmaceuticalcomposition comprising a pharmaceutically effective amount of at leastone antiemetic, where the antiemetic is a 5-HT3 antagonist and/or a NK-1antagonist, or pharmaceutically acceptable salt thereof, and a ChEI asdescribed herein.

Thus, according to one aspect, the present invention providespharmaceutical compositions including, as one of the active ingredients,at least one pharmacologically active amount of an antiemetic, where theantiemetic is a 5-HT3 antagonist and/or a NK-1 antagonist, as shownabove or of one of its pharmaceutically acceptable salts, in mixturewith a pharmaceutical carrier or vehicle.

In the pharmaceutical compositions of the present invention for oral,subcutaneous, intravenous, transdermal or topical administration, theactive ingredient is preferably administered in the form of dosageunits, in mixture with the classic pharmaceutical carriers or vehicles.

A suitable dosage amount of the pharmaceutical composition of thepresent invention can vary depending on pharmaceutical formulationmethods, administration methods, the patient's age, weight, sex, healthcondition of the patient, diet, administration time, administrationroute, an excretion rate and sensitivity for a used pharmaceuticalcomposition. For instance, the dosage of the antiemetic, where theantiemetic is a 5-HT3 antagonist and/or a NK-1 antagonist, may bedetermined in accordance with the respective potency of each antagonistand the age of the patient, and administered from one to several times aday by intravenous, subcutaneous, oral, or transcutaneousadministration. For 5-HT3 antagonists, said dosage will range from 1 μgto 300 mg.

The pharmaceutical compositions of the present invention are formulatedwith classic pharmaceutical excipients suitable for the different waysof administration. Particularly advantageous are the formulations in theform of tablets, multi-score tablets, coated tables, orallydisintegrating tablets, extended release tablets, hard or soft capsules,extended-release capsules, patches for transdermal administration,liquid oral solutions, syrups or suspensions in a predetermined unitform, and vials for intravenous, intramuscular, or subcutaneousadministration.

The pharmaceutical composition of this invention includes apharmaceutically acceptable carrier besides an antiemetic, where theantiemetic is a 5-HT3 antagonist and/or a NK-1 antagonist, orpharmaceutically acceptable salt thereof as the active ingredient. Thepharmaceutically acceptable carrier contained in the pharmaceuticalcomposition of the present invention, which is commonly used inpharmaceutical formulations. Suitable pharmaceutically acceptablecarriers and formulations can be found in Remington's PharmaceuticalSciences (22^(nd) ed., 2013), which is herein incorporated by referencein its entirety.

According to the conventional techniques known to those skilled in theart, the pharmaceutical composition according to the present inventionmay be formulated with pharmaceutically acceptable carrier and/orvehicle as described above, to provide dosage forms including a unitdose form and a multi-dose form. Non-limiting examples of theformulations include, but not limited to, a solution, a suspension or anemulsion in oil or aqueous medium, an elixir, a powder, a granule, atablet and a capsule.

The invention further relates to a transdermal therapeutic systemcomprising an antiemetic, where the antiemetic is a 5-HT3 antagonist ora NK-1 antagonist, or pharmaceutically acceptable salt thereof, and anChEI as described herein. Alternatively, the invention relates to atransdermal therapeutic system comprising an antiemetic combination,where the antiemetic combination is a 5-HT3 antagonist and a NK-1antagonist, or pharmaceutically acceptable salt thereof, and an ChEI asdescribed herein. In particular, the transdermal therapeutic systeminvolves delivering said antiemetic or said antiemetic combination witha high-dose of an ChEI and in particular, an AChEI in some preferredembodiments, via transdermal formulation(s) and transdermal patchesincorporating such formulations. The present invention also relates totransdermal drug formulations, transdermal patches incorporating suchformulations, as well as associated methods of use for improving theprotection of humans and other mammals at risk of being exposed to OPcompounds, and methods for treating, preventing, or alleviating aneffect of an OP compound in humans and other mammals exposed to an OPcompound. The formulations of the present invention can be incorporatedinto patches for transdermal administration. For instance, a transdermalpatch for transdermal delivery of said antiemetic and a transdermalpatch for transdermal delivery of an acetylcholine esterase inhibitor.Alternatively, the transdermal patch for transdermal delivery of saidantiemetic is combined with an orally administered ChEI, or, atransdermal patch for transdermal delivery of ChEI is combined with oraladministration of said antiemetic.

In yet another embodiment, the dose of the ChEI may be higher than themaximum recommended daily dose, in particular from 1.1 to 10 timeshigher than a recommended maximal daily dose level; or, the acetylcholine esterase inhibitor may be higher than the maximal tolerateddose, in particular, from 1.1 to 10 times higher than the maximaltolerated dose. The “maximum tolerated dose,” “maximal tolerated dose”or “MTD” refers to, and is defined as the highest dose of a drug ortreatment that does not cause unacceptable side effects. The maximumtolerated dose is determined in clinical trials by testing increasingdoses on different groups of people until the highest dose withacceptable side effects is found

Thus, for example, using 5-HT3 antagonists, a pharmaceutical compositionaccording to the present invention to be chronically or recurrentlyadministered in combination with pyridostigmine may comprise azasetronhydrochloride, in an amount of from 5 mg to 10 mg to be administered ata daily dose of from 15 mg to 40 mg; dolasetron mesylate, in an amountof from 25 mg to 200 mg to be administered at a daily dose of from 75 mgto 800 mg; granisetron hydrochloride, in an amount equivalent to from0.5 mg to 2 mg granisetron base, to be administered at a daily dose offrom 1.5 mg to 8 mg; ondansetron hydrochloride dihydrate, in an amountequivalent to from 2 mg to 8 mg ondansetron base, to be administered ata daily dose of from 8 to 12 mg; palonosetron hydrochloride, in anamount equivalent to from 0.25 mg to 0.5 mg palonosetron base, to beadministered at a daily dose of from 0.75 to 2 mg; tropisetronhydrochloride, in an amount equivalent to from 2.5 mg to 5 mgtropisetron base, to be administered at a daily dose of from 7.5 to 20mg. Similarly, for NK-1 antagonists, a pharmaceutical compositionaccording to the present invention to be chronically or recurrentlyadministered in combination with pyridostigmine may comprise antagonistsof the NK-1 receptor that are approved for the prevention or treatmentof postoperative nausea and vomiting or for the prevention ofchemotherapy-induced nausea and vomiting. Thus, for example, apharmaceutical composition according to the present invention to bechronically or recurrently administered in combination withpyridostigmine may comprise aprepitant at a daily oral dose of from 80mg to 120 mg; rolapitant, at a daily oral dose of from 30 mg to 270 mgor netupitant 300 mg/palonosetron 0.5 mg, orally administered once aday.

In the case of pediatric or obese patients, the daily dose may bedetermined based on body weight. Thus, for example, for 5-HT3antagonists, azasetron hydrochloride may be administered at a daily doseof 0.4-0.5 mg/kg, dolasetron mesylate may be administered at a dailydose of 9-9.5 mg/kg, granisetron hydrochloride may be administered at adaily dose of 0.09-0.11 mg/kg, ondansetron hydrochloride dihydrate maybe administered at a daily dose of 0.114-0.171 mg/kg, palonosetronhydrochloride may be administered at a daily dose of 0.03 mg/kg andtropisetron hydrochloride may be administered at a daily dose of 0.5-0.6mg/kg. Similarly, for example, for NK-1 antagonists, aprepitant may beadministered at a daily dose of 1.14-1.71 mg/kg daily, and rolapitantmay be administered at a daily dose of 2-18 mg/kg.

According to another aspect of the present invention, the pharmaceuticalcomposition comprising an antiemetic may contain another activeingredient, in particular, a pharmaceutically acceptable salt ofpyridostigmine, co-formulated with said. NK-1 antagonist, in admixturewith a pharmaceutical carrier.

EXAMPLES Example 1

The ability of a 5-HT3 antagonist for preventing the adverse effects ofpyridostigmine bromide in humans was tested.

A Phase I study was conducted in human subjects receiving an oral doseof pyridostigmine bromide with or without an oral dose of ondansetronhydrochloride dihydrate, as a representative 5-HT3 antagonist. The studywas a single center, single-blind, placebo-controlled study.

The objective of the study was to demonstrate the safe attenuation byondansetron, of gastro-intestinal side effects of pyridostigmine givenin doses demonstrated to be effective for the treatment of OP poisoning.To be enrolled in the study, participants (aged 18 to 60 years of age)were required to be in good health, to refrain from consuming xanthine,quinine and caffeine containing beverages, and to refrain from prolongedintensive physical exercise during the study conduct. All subjectssigned an informed consent form indicating that they understood thepurpose of, and the procedures required for the study, and that theywere willing to participate in the study and comply with the studyprocedures and restrictions. The key criteria for exclusion of a subjectfrom enrollment in the study were as follows:

-   -   any clinically relevant acute or chronic disease which could        interfere with the subjects' safety during the trial, expose        them to undue risk, or interfere with the study objectives;    -   history or presence of gastrointestinal, hepatic, or renal        disease or other condition known to interfere with the        absorption, distribution, metabolism or excretion of drugs;    -   history of substance abuse, known drug addiction, or positive        test for drugs of abuse or alcohol;    -   history of drug or other significant allergy;    -   ECG changes including QT interval prolongation and congenital        long QT syndrome. Electrolyte abnormalities (e.g., hypokalemia        or hypomagnesemia), congestive heart failure, bradyarrhythmias        or other conditions that lead to QT prolongation;    -   treatment with centrally active drugs or those affecting        peripheral cholinergic transmission within 3 months of study        entry;    -   smokers (except subjects who stopped smoking 1 year or more        before enrollment in the Study);    -   excessive daily consumption of xanthines containing drinks        (i.e. >500 mg/day of caffeine);    -   intake of an investigational drug within 30 days of study entry.

Following enrollment in the study, participants received oral doses ofpyridostigmine, with the total dose per day being increased on a dailybasis. Once a subject had reached his/her first intolerable daily dose,dosing was discontinued for wash-out. First intolerable dose was definedas an amount inducing at least one of the following:

-   -   (a) one episode of vomiting; or    -   (b) two episodes of retching; or    -   (c) one episode of severe nausea; or    -   (d) one episode of moderate diarrhea (Grade 2).

Following a wash-out for 2 to 7 days, participants then received theirfirst intolerable dose of pyridostigmine plus a single oral dose ofondansetron hydrochloride dihydrate (10 mg, equivalent to 8 mgondansetron base) or ondansetron placebo, and the dose of pyridostigminewas again titrated up on a daily basis to a second intolerable dose(FID-2). The highest tolerated daily dose of pyridostigmine whenadministered with ondansetron is defined as the tolerated dose achievedjust before FID-2).

On each study day, subjects were followed up for up to 8 hours for AEs,vital signs, ECGs, and a laboratory panel at screening and at the end ofthe study.

Results showed that the co-administration of ondansetron withpyridostigmine at FID attenuated gastro-intestinal AEs reported withpyridostigmine alone at FID. Furthermore, in the presence ofondansetron, higher doses of pyridostigmine could be tolerably given,with the highest tolerated daily dose generally exceeding therecommended dose for the treatment of OP poisoning.

In conclusion, the co-administration of oral high dose ondansetron withpyridostigmine prevented the occurrence of gastro-intestinal AEs whenpyridostigmine was given in doses as high as or higher than therecommended efficacious dose for the treatment of OP poisoning.

Example 2

The ability of a NK-1 antagonist for preventing the adverse effects ofpyridostigmine bromide in humans was tested.

A Phase I study was conducted in human subjects receiving a single oraldose of pyridostigmine bromide with or without a single oral dose ofaprepitant, as a representative NK-1 receptor antagonist. The study wasa single center, single-blind, placebo-controlled study.

The objective of the study was to demonstrate the safe attenuation byaprepitant, of gastro-intestinal side effects of pyridostigmine given indoses demonstrated to be effective for the treatment of OP poisoning. Tobe enrolled in the study, participants (aged 18 to 60 years of age) wererequired to be in good health, to refrain from consuming xanthine,quinine and caffeine containing beverages, and to refrain from prolongedintensive physical exercise during the study conduct. All subjectssigned an informed consent form indicating that they understood thepurpose of, and the procedures required for the study, and that theywere willing to participate in the study and comply with the studyprocedures and restrictions. The key criteria for exclusion of a subjectfrom enrollment in the study were as follows:

-   -   any clinically relevant acute or chronic disease which could        interfere with the subjects' safety during the trial, expose        them to undue risk, or interfere with the study objectives;    -   history or presence of gastrointestinal, hepatic, or renal        disease or other condition known to interfere with the        absorption, distribution, metabolism or excretion of drugs;    -   history of substance abuse, known drug addiction, or positive        test for drugs of abuse or alcohol;    -   history of drug or other significant allergy;    -   ECG changes including QT interval prolongation and congenital        long QT syndrome. Electrolyte abnormalities (e.g., hypokalemia        or hypomagnesemia), congestive heart failure, bradyarrhythmias        or other conditions that lead to QT prolongation;    -   treatment with centrally active drugs or those affecting        peripheral cholinergic transmission within 3 months of study        entry;    -   smokers (except subjects who stopped smoking 1 year or more        before enrollment in the Study);    -   excessive daily consumption of xanthines containing drinks        (i.e. >500 mg/day of caffeine);    -   intake of an investigational drug within 30 days of study entry.

Following enrollment in the study, participants received singleincreasing oral doses of pyridostigmine, given once daily in themorning. Once a subject had reached his/her first intolerable dose,upward dose escalation was discontinued. First intolerable dose wasdefined as an amount inducing at least one of the following:

-   -   (a) one episode of vomiting; or    -   (b) two episodes of retching; or    -   (c) one episode of severe nausea; or    -   (d) one episode of moderate diarrhea (Grade 2).

Following a wash-out, participants then entered Period 2 of the studyduring which they received single increasing doses of oralpyridostigmine given daily in the morning with a single dose ofaprepitant (80 mg to 120 mg) until they reached an intolerable dose ofpyridostigmine as defined above (FID-2)

On each study day, subjects were followed up for up to 8 hours for AEs,vital signs, ECGs, and a laboratory panel at screening and at the end ofthe study.

Results showed that the co-administration of aprepitant withpyridostigmine at FID attenuated gastro-intestinal AEs reported withpyridostigmine alone at FID. Furthermore, in the presence of aprepitant,higher doses of pyridostigmine could be tolerably given, with thehighest tolerated daily dose generally exceeding the recommended dosefor the treatment of OP poisoning.

In conclusion, the co-administration of oral aprepitant withpyridostigmine prevented the occurrence of gastro-intestinal AEs givenin doses as high as or higher than (up to 6 times) the recommendedefficacious dose for the treatment of OP poisoning.

REFERENCES

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1. A method for protecting against toxicity from a nerve agent in asubject at risk of exposure to a nerve agent, or preventing oralleviating/reducing toxicity from a nerve agent in a subject exposed toa nerve agent, comprising administering to said subject an effectivedaily dose of an antiemetic selected from the group consisting of 5-HT3antagonists and NK-1 antagonists, including pharmaceutically acceptablesalts thereof, in combination with an effective daily dose of a cholineesterase inhibitor or pharmaceutically acceptable salt thereof. 2.(canceled)
 3. The method of claim 1, wherein the choline esteraseinhibitor is pyridostigmine or a pharmaceutically acceptable saltthereof.
 4. The method of claim 1, wherein the choline esteraseinhibitor is neostigmine or a pharmaceutically acceptable salt thereof.5. The method of claim 1, wherein the choline esterase inhibitor isphysostigmine or a pharmaceutically acceptable salt thereof.
 6. Themethod of claim 1, wherein the choline esterase inhibitor isrivastigmine or a pharmaceutically acceptable salt thereof.
 7. Themethod of claim 1, wherein said NK-1 antagonist is selected from thegroup consisting of fosaprepitant, casopitant, aprepitant, rolapitant,maropitant, eziopitant, lanepitant, netupitant, orvepitant, serlopitant,vestipitant, vofopitant, and pharmaceutically acceptable salts orsolvates thereof.
 8. The method of claim 1, wherein said NK-1 antagonistis aprepitant or a pharmaceutically acceptable salt or solvate thereof.9. The method of claim 3, wherein said NK-1 antagonist is rolapitant ora pharmaceutically acceptable salt or solvate thereof.
 10. The method ofclaim 1, wherein said 5-HT3 antagonist is ondansetron or apharmaceutically acceptable salt or solvate thereof.
 11. The method ofclaim 3, wherein said 5-HT3 antagonist is ondansetron or apharmaceutically acceptable salt or solvate thereof.
 12. Apharmaceutical composition comprising an effective daily dose of anantiemetic and an effective daily dose of a choline esterase inhibitor.13. The pharmaceutical composition of claim 12, wherein an theantiemetic I selected from a 5-HT3 antagonist and a NK-1 antagonist. 14.The pharmaceutical composition of claim 13, wherein the antiemetic is a5-HT3 antagonist in an amount up to 10 times a pediatric or adult doseapproved for the prevention of chemotherapy-induced nausea and vomiting.15. The pharmaceutical composition of claim 13, where in the antiemeticis a NK-1 antagonist in an amount up to 6 times a pediatric or adultdose approved for the prevention of chemotherapy-induced nausea andvomiting.
 16. A pharmaceutical composition comprising an antiemeticcombination and an effective daily dose of a choline esterase inhibitor.17. The pharmaceutical composition of claim 16, wherein the antiemeticcombination is a 5-HT3 antagonist and a NK-1 antagonist.
 18. Thepharmaceutical composition of claim 17, wherein the 5-HT3 antagonist isin an amount up to 10 times a pediatric or adult dose approved for theprevention of chemotherapy-induced nausea and vomiting.
 19. Thepharmaceutical composition of claim 17, wherein the NK-1 antagonist isin an amount up to 6 times a pediatric or adult dose approved for theprevention of chemotherapy-induced nausea and vomiting.
 20. Use of thepharmaceutical composition of claim 12, for protecting against toxicityfrom a nerve agent in a subject at risk of exposure to a nerve agent, orpreventing or alleviating/reducing toxicity from a nerve agent in asubject exposed to a nerve agent.